The invention relates to a sanitary insert unit which is fittable on the water outlet of a sanitary outlet fitting and has a flow-restricting or control device with a flow-restricting or control element.
Sanitary insert units which are insertable into an outlet mouthpiece in order to be fitted with said outlet mouthpiece on the water outlet of a sanitary outlet fitting are already known. The previously known insert units have a throughflow-quantity regulator, with an attachment screen or filter screen connected upstream thereof on the inflow side and a jet regulator is arranged downstream thereof on the outflow side. While the throughflow-quantity regulator has to adjust the water flowing therethrough to a fixed, maximum throughflow capacity irrespective of the pressure, the jet regulator of the previously known insert unit is intended to shape the outflowing water to form a homogeneous, non-sputtering and optionally also sparkling-soft water jet. The lime and dirt particles entrained in the water which could otherwise impair the correct functioning of the throughflow-quantity regulator and/or the jet regulator are filtered out with the aid of the attachment screen or filter screen connected upstream on the inflow side.
The throughflow-quantity regulators used in the previously known insert units generally have an annular flow-restricting body made from elastically deformable material, which, between itself and a central flow-restricting or control core, bounds a control gap which can be varied under the pressure of the water flowing therethrough. For this purpose, on the circumferential side, the control core has a control profiling, into which the elastically deformable flow-restricting body is increasingly molded, as the pressure of the water flowing therethrough increases, in such a manner that, even at high water pressures, a fixed maximum value of the throughflow capacity is not exceeded. At low water pressures which do not yet bring about a deformation of the elastic flow-restricting body, the previously known throughflow-quantity regulators constitute, however, a flow obstacle which additionally also restricts the quantity of water flowing therethrough.
Sanitary insert units of the type mentioned at the beginning have been made, in which the core which is profiled on the circumferential side is guided displaceably under the pressure of the water flowing therethrough from a starting position counter to a restoring force into a control position. While, in the control position, the elastically deformable flow-restricting body and the profiled control core are arranged in a functionally correct manner with respect to each other, in the unloaded starting position the profiled control core is in a screen interior which bounds the hat or plate-shaped attachment screen. Since a compression spring which also acts in the starting position on the flow-restricting or control core and presses said flow-restricting or control core in the direction of the attachment screen on the inflow side is provided as the restoring force, there is the risk that the attachment screen or filter screen becomes separated from the remaining constituent parts of the previously known insert unit and said insert unit falls apart.